• Support PF! Buy your school textbooks, materials and every day products Here!

Theoretical and Actual Acceleration for an Atwood Machine

  • Thread starter Pandaluvv2
  • Start date
  • #1

Homework Statement



Include free body diagrams and equations solved independently for acceleration and tension. Note: a and T are to be expressed in terms of m1, m2, and g only.
Trial 1:Mass1= 55g and Mass2= 60g
Trial 2:Mass1= 55g and Mass2= 65g
We are doing 2 trials but i need help with the first one. I'm not sure how to figure out the acceleration and theoretical acceleration, should they be coming out the same?


Homework Equations



A=(m2-m1/m1+m2)g
Ath=g(m2-m1/m1+m2)
T=(2m1m2/m1+m2)g

The Attempt at a Solution



Trial 1: A=((60-55)/(60+55))*9.8 = (5/115)*9.8 = 0.426m/s/s
Ath=9.8*((60-55)/(60+55)) = 9.8*(5/115) = 0.4260m/s/s
T=(2*55*60/55+60)9.8 = (6600/115)*9.8 = 562.43N
 
Last edited:

Answers and Replies

  • #2
gneill
Mentor
20,792
2,770
Hi Pandaluvv2, welcome to Physics Forums.

Is this assignment accompanying a hands-on lab? If so, the "actual acceleration" would be the value you measure during the experiment, which would subsequently be compared to the theoretical value that you calculate.

The formulas that you've arrived at appear to be okay but you need to be careful with the units. Your masses are given in grams but should be converted to kilograms for use in the tension formula. The scaling factors happen to cancel out in the acceleration formula so your result turns out to be correct, but you should be using kilograms there too.
 
  • #3
Okay, that makes sense, I forgot we had found acceleration during class, which would have saved me a bunch of time. The only thing I should change is my mass to kilograms then right? So I can use it for the tension?
 
  • #4
gneill
Mentor
20,792
2,770
Okay, that makes sense, I forgot we had found acceleration during class, which would have saved me a bunch of time. The only thing I should change is my mass to kilograms then right? So I can use it for the tension?
Yup. Work in kilograms.
 
  • #5
Okay, thank you very much for the help!
 

Related Threads on Theoretical and Actual Acceleration for an Atwood Machine

Replies
9
Views
4K
Replies
6
Views
11K
Replies
12
Views
40K
  • Last Post
Replies
15
Views
6K
Replies
5
Views
4K
  • Last Post
Replies
1
Views
3K
  • Last Post
2
Replies
26
Views
1K
  • Last Post
Replies
4
Views
2K
Replies
1
Views
2K
Replies
2
Views
1K
Top